net/bridge/br_netlink.c

   1 /*
   2  *      Bridge netlink control interface
   3  *
   4  *      Authors:
   5  *      Stephen Hemminger               <shemminger@osdl.org>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/etherdevice.h>
  16 #include <net/rtnetlink.h>
  17 #include <net/net_namespace.h>
  18 #include <net/sock.h>
  19
  20 #include "br_private.h"
  21 #include "br_private_stp.h"
  22
  23 static inline size_t br_port_info_size(void)
  24 {
  25         return nla_total_size(1)        /* IFLA_BRPORT_STATE  */
  26                 + nla_total_size(2)     /* IFLA_BRPORT_PRIORITY */
  27                 + nla_total_size(4)     /* IFLA_BRPORT_COST */
  28                 + nla_total_size(1)     /* IFLA_BRPORT_MODE */
  29                 + nla_total_size(1)     /* IFLA_BRPORT_GUARD */
  30                 + nla_total_size(1)     /* IFLA_BRPORT_PROTECT */
  31                 + 0;
  32 }
  33
  34 static inline size_t br_nlmsg_size(void)
  35 {
  36         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  37                 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  38                 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  39                 + nla_total_size(4) /* IFLA_MASTER */
  40                 + nla_total_size(4) /* IFLA_MTU */
  41                 + nla_total_size(4) /* IFLA_LINK */
  42                 + nla_total_size(1) /* IFLA_OPERSTATE */
  43                 + nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
  44 }
  45
  46 static int br_port_fill_attrs(struct sk_buff *skb,
  47                               const struct net_bridge_port *p)
  48 {
  49         u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
  50
  51         if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
  52             nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
  53             nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
  54             nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
  55             nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
  56             nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)) ||
  57             nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)))
  58                 return -EMSGSIZE;
  59
  60         return 0;
  61 }
  62
  63 /*
  64  * Create one netlink message for one interface
  65  * Contains port and master info as well as carrier and bridge state.
  66  */
  67 static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port,
  68                           u32 pid, u32 seq, int event, unsigned int flags)
  69 {
  70         const struct net_bridge *br = port->br;
  71         const struct net_device *dev = port->dev;
  72         struct ifinfomsg *hdr;
  73         struct nlmsghdr *nlh;
  74         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  75
  76         br_debug(br, "br_fill_info event %d port %s master %s\n",
  77                      event, dev->name, br->dev->name);
  78
  79         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  80         if (nlh == NULL)
  81                 return -EMSGSIZE;
  82
  83         hdr = nlmsg_data(nlh);
  84         hdr->ifi_family = AF_BRIDGE;
  85         hdr->__ifi_pad = 0;
  86         hdr->ifi_type = dev->type;
  87         hdr->ifi_index = dev->ifindex;
  88         hdr->ifi_flags = dev_get_flags(dev);
  89         hdr->ifi_change = 0;
  90
  91         if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
  92             nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
  93             nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
  94             nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
  95             (dev->addr_len &&
  96              nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
  97             (dev->ifindex != dev->iflink &&
  98              nla_put_u32(skb, IFLA_LINK, dev->iflink)))
  99                 goto nla_put_failure;
 100
 101         if (event == RTM_NEWLINK) {
 102                 struct nlattr *nest
 103                         = nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
 104
 105                 if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
 106                         goto nla_put_failure;
 107                 nla_nest_end(skb, nest);
 108         }
 109
 110         return nlmsg_end(skb, nlh);
 111
 112 nla_put_failure:
 113         nlmsg_cancel(skb, nlh);
 114         return -EMSGSIZE;
 115 }
 116
 117 /*
 118  * Notify listeners of a change in port information
 119  */
 120 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 121 {
 122         struct net *net = dev_net(port->dev);
 123         struct sk_buff *skb;
 124         int err = -ENOBUFS;
 125
 126         br_debug(port->br, "port %u(%s) event %d\n",
 127                  (unsigned int)port->port_no, port->dev->name, event);
 128
 129         skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
 130         if (skb == NULL)
 131                 goto errout;
 132
 133         err = br_fill_ifinfo(skb, port, 0, 0, event, 0);
 134         if (err < 0) {
 135                 /* -EMSGSIZE implies BUG in br_nlmsg_size() */
 136                 WARN_ON(err == -EMSGSIZE);
 137                 kfree_skb(skb);
 138                 goto errout;
 139         }
 140         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 141         return;
 142 errout:
 143         if (err < 0)
 144                 rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 145 }
 146
 147 /*
 148  * Dump information about all ports, in response to GETLINK
 149  */
 150 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 151                struct net_device *dev)
 152 {
 153         int err = 0;
 154         struct net_bridge_port *port = br_port_get_rcu(dev);
 155
 156         /* not a bridge port */
 157         if (!port)
 158                 goto out;
 159
 160         err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI);
 161 out:
 162         return err;
 163 }
 164
 165 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
 166         [IFLA_BRPORT_STATE]     = { .type = NLA_U8 },
 167         [IFLA_BRPORT_COST]      = { .type = NLA_U32 },
 168         [IFLA_BRPORT_PRIORITY]  = { .type = NLA_U16 },
 169         [IFLA_BRPORT_MODE]      = { .type = NLA_U8 },
 170         [IFLA_BRPORT_GUARD]     = { .type = NLA_U8 },
 171         [IFLA_BRPORT_PROTECT]   = { .type = NLA_U8 },
 172 };
 173
 174 /* Change the state of the port and notify spanning tree */
 175 static int br_set_port_state(struct net_bridge_port *p, u8 state)
 176 {
 177         if (state > BR_STATE_BLOCKING)
 178                 return -EINVAL;
 179
 180         /* if kernel STP is running, don't allow changes */
 181         if (p->br->stp_enabled == BR_KERNEL_STP)
 182                 return -EBUSY;
 183
 184         if (!netif_running(p->dev) ||
 185             (!netif_carrier_ok(p->dev) && state != BR_STATE_DISABLED))
 186                 return -ENETDOWN;
 187
 188         p->state = state;
 189         br_log_state(p);
 190         br_port_state_selection(p->br);
 191         return 0;
 192 }
 193
 194 /* Set/clear or port flags based on attribute */
 195 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 196                            int attrtype, unsigned long mask)
 197 {
 198         if (tb[attrtype]) {
 199                 u8 flag = nla_get_u8(tb[attrtype]);
 200                 if (flag)
 201                         p->flags |= mask;
 202                 else
 203                         p->flags &= ~mask;
 204         }
 205 }
 206
 207 /* Process bridge protocol info on port */
 208 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 209 {
 210         int err;
 211
 212         br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 213         br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
 214         br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
 215
 216         if (tb[IFLA_BRPORT_COST]) {
 217                 err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
 218                 if (err)
 219                         return err;
 220         }
 221
 222         if (tb[IFLA_BRPORT_PRIORITY]) {
 223                 err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
 224                 if (err)
 225                         return err;
 226         }
 227
 228         if (tb[IFLA_BRPORT_STATE]) {
 229                 err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
 230                 if (err)
 231                         return err;
 232         }
 233         return 0;
 234 }
 235
 236 /* Change state and parameters on port. */
 237 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 238 {
 239         struct ifinfomsg *ifm;
 240         struct nlattr *protinfo;
 241         struct net_bridge_port *p;
 242         struct nlattr *tb[IFLA_BRPORT_MAX + 1];
 243         int err;
 244
 245         ifm = nlmsg_data(nlh);
 246
 247         protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
 248         if (!protinfo)
 249                 return 0;
 250
 251         p = br_port_get_rtnl(dev);
 252         if (!p)
 253                 return -EINVAL;
 254
 255         if (protinfo->nla_type & NLA_F_NESTED) {
 256                 err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
 257                                        protinfo, ifla_brport_policy);
 258                 if (err)
 259                         return err;
 260
 261                 spin_lock_bh(&p->br->lock);
 262                 err = br_setport(p, tb);
 263                 spin_unlock_bh(&p->br->lock);
 264         } else {
 265                 /* Binary compatability with old RSTP */
 266                 if (nla_len(protinfo) < sizeof(u8))
 267                         return -EINVAL;
 268
 269                 spin_lock_bh(&p->br->lock);
 270                 err = br_set_port_state(p, nla_get_u8(protinfo));
 271                 spin_unlock_bh(&p->br->lock);
 272         }
 273
 274         if (err == 0)
 275                 br_ifinfo_notify(RTM_NEWLINK, p);
 276
 277         return err;
 278 }
 279
 280 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
 281 {
 282         if (tb[IFLA_ADDRESS]) {
 283                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 284                         return -EINVAL;
 285                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 286                         return -EADDRNOTAVAIL;
 287         }
 288
 289         return 0;
 290 }
 291
 292 struct rtnl_link_ops br_link_ops __read_mostly = {
 293         .kind           = "bridge",
 294         .priv_size      = sizeof(struct net_bridge),
 295         .setup          = br_dev_setup,
 296         .validate       = br_validate,
 297         .dellink        = br_dev_delete,
 298 };
 299
 300 int __init br_netlink_init(void)
 301 {
 302         return rtnl_link_register(&br_link_ops);
 303 }
 304
 305 void __exit br_netlink_fini(void)
 306 {
 307         rtnl_link_unregister(&br_link_ops);
 308 }